Metamath Proof Explorer


Theorem fsumiunle

Description: Upper bound for a sum of nonnegative terms over an indexed union. The inequality may be strict if the indexed union is non-disjoint, since in the right hand side, a summand may be counted several times. (Contributed by Thierry Arnoux, 1-Jan-2021)

Ref Expression
Hypotheses fsumiunle.1 ( 𝜑𝐴 ∈ Fin )
fsumiunle.2 ( ( 𝜑𝑥𝐴 ) → 𝐵 ∈ Fin )
fsumiunle.3 ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑘𝐵 ) → 𝐶 ∈ ℝ )
fsumiunle.4 ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑘𝐵 ) → 0 ≤ 𝐶 )
Assertion fsumiunle ( 𝜑 → Σ 𝑘 𝑥𝐴 𝐵 𝐶 ≤ Σ 𝑥𝐴 Σ 𝑘𝐵 𝐶 )

Proof

Step Hyp Ref Expression
1 fsumiunle.1 ( 𝜑𝐴 ∈ Fin )
2 fsumiunle.2 ( ( 𝜑𝑥𝐴 ) → 𝐵 ∈ Fin )
3 fsumiunle.3 ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑘𝐵 ) → 𝐶 ∈ ℝ )
4 fsumiunle.4 ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑘𝐵 ) → 0 ≤ 𝐶 )
5 1 2 aciunf1 ( 𝜑 → ∃ 𝑓 ( 𝑓 : 𝑥𝐴 𝐵1-1 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) )
6 f1f1orn ( 𝑓 : 𝑥𝐴 𝐵1-1 𝑥𝐴 ( { 𝑥 } × 𝐵 ) → 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 )
7 6 anim1i ( ( 𝑓 : 𝑥𝐴 𝐵1-1 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) → ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) )
8 f1f ( 𝑓 : 𝑥𝐴 𝐵1-1 𝑥𝐴 ( { 𝑥 } × 𝐵 ) → 𝑓 : 𝑥𝐴 𝐵 𝑥𝐴 ( { 𝑥 } × 𝐵 ) )
9 8 frnd ( 𝑓 : 𝑥𝐴 𝐵1-1 𝑥𝐴 ( { 𝑥 } × 𝐵 ) → ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) )
10 9 adantr ( ( 𝑓 : 𝑥𝐴 𝐵1-1 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) → ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) )
11 7 10 jca ( ( 𝑓 : 𝑥𝐴 𝐵1-1 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) → ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) )
12 11 eximi ( ∃ 𝑓 ( 𝑓 : 𝑥𝐴 𝐵1-1 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) → ∃ 𝑓 ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) )
13 5 12 syl ( 𝜑 → ∃ 𝑓 ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) )
14 csbeq1a ( 𝑘 = 𝑦𝐶 = 𝑦 / 𝑘 𝐶 )
15 nfcv 𝑦 𝐶
16 nfcsb1v 𝑘 𝑦 / 𝑘 𝐶
17 14 15 16 cbvsum Σ 𝑘 𝑥𝐴 𝐵 𝐶 = Σ 𝑦 𝑥𝐴 𝐵 𝑦 / 𝑘 𝐶
18 csbeq1 ( 𝑦 = ( 2nd𝑧 ) → 𝑦 / 𝑘 𝐶 = ( 2nd𝑧 ) / 𝑘 𝐶 )
19 snfi { 𝑥 } ∈ Fin
20 xpfi ( ( { 𝑥 } ∈ Fin ∧ 𝐵 ∈ Fin ) → ( { 𝑥 } × 𝐵 ) ∈ Fin )
21 19 2 20 sylancr ( ( 𝜑𝑥𝐴 ) → ( { 𝑥 } × 𝐵 ) ∈ Fin )
22 21 ralrimiva ( 𝜑 → ∀ 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∈ Fin )
23 iunfi ( ( 𝐴 ∈ Fin ∧ ∀ 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∈ Fin ) → 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∈ Fin )
24 1 22 23 syl2anc ( 𝜑 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∈ Fin )
25 24 adantr ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ∈ Fin )
26 simprr ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) )
27 25 26 ssfid ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → ran 𝑓 ∈ Fin )
28 simprl ( ( 𝜑 ∧ ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 )
29 f1ocnv ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 𝑓 : ran 𝑓1-1-onto 𝑥𝐴 𝐵 )
30 28 29 syl ( ( 𝜑 ∧ ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → 𝑓 : ran 𝑓1-1-onto 𝑥𝐴 𝐵 )
31 30 adantrlr ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → 𝑓 : ran 𝑓1-1-onto 𝑥𝐴 𝐵 )
32 nfv 𝑥 𝜑
33 nfcv 𝑥 𝑓
34 nfiu1 𝑥 𝑥𝐴 𝐵
35 33 nfrn 𝑥 ran 𝑓
36 33 34 35 nff1o 𝑥 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓
37 nfv 𝑥 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙
38 34 37 nfralw 𝑥𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙
39 36 38 nfan 𝑥 ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 )
40 nfcv 𝑥 ran 𝑓
41 nfiu1 𝑥 𝑥𝐴 ( { 𝑥 } × 𝐵 )
42 40 41 nfss 𝑥 ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 )
43 39 42 nfan 𝑥 ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) )
44 32 43 nfan 𝑥 ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) )
45 nfv 𝑥 𝑧 ∈ ran 𝑓
46 44 45 nfan 𝑥 ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 )
47 simpr ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → ( 𝑓𝑘 ) = 𝑧 )
48 47 fveq2d ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → ( 2nd ‘ ( 𝑓𝑘 ) ) = ( 2nd𝑧 ) )
49 simplr ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → 𝑘 𝑥𝐴 𝐵 )
50 simp-4r ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) )
51 50 simpld ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) )
52 51 simprd ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 )
53 52 ad2antrr ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 )
54 2fveq3 ( 𝑙 = 𝑘 → ( 2nd ‘ ( 𝑓𝑙 ) ) = ( 2nd ‘ ( 𝑓𝑘 ) ) )
55 id ( 𝑙 = 𝑘𝑙 = 𝑘 )
56 54 55 eqeq12d ( 𝑙 = 𝑘 → ( ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ↔ ( 2nd ‘ ( 𝑓𝑘 ) ) = 𝑘 ) )
57 56 rspcva ( ( 𝑘 𝑥𝐴 𝐵 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) → ( 2nd ‘ ( 𝑓𝑘 ) ) = 𝑘 )
58 49 53 57 syl2anc ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → ( 2nd ‘ ( 𝑓𝑘 ) ) = 𝑘 )
59 48 58 eqtr3d ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → ( 2nd𝑧 ) = 𝑘 )
60 51 simpld ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 )
61 60 ad2antrr ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 )
62 f1ocnvfv1 ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓𝑘 𝑥𝐴 𝐵 ) → ( 𝑓 ‘ ( 𝑓𝑘 ) ) = 𝑘 )
63 61 49 62 syl2anc ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → ( 𝑓 ‘ ( 𝑓𝑘 ) ) = 𝑘 )
64 47 fveq2d ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → ( 𝑓 ‘ ( 𝑓𝑘 ) ) = ( 𝑓𝑧 ) )
65 59 63 64 3eqtr2rd ( ( ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) ∧ 𝑘 𝑥𝐴 𝐵 ) ∧ ( 𝑓𝑘 ) = 𝑧 ) → ( 𝑓𝑧 ) = ( 2nd𝑧 ) )
66 f1ofn ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓𝑓 Fn 𝑥𝐴 𝐵 )
67 60 66 syl ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → 𝑓 Fn 𝑥𝐴 𝐵 )
68 simpllr ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → 𝑧 ∈ ran 𝑓 )
69 fvelrnb ( 𝑓 Fn 𝑥𝐴 𝐵 → ( 𝑧 ∈ ran 𝑓 ↔ ∃ 𝑘 𝑥𝐴 𝐵 ( 𝑓𝑘 ) = 𝑧 ) )
70 69 biimpa ( ( 𝑓 Fn 𝑥𝐴 𝐵𝑧 ∈ ran 𝑓 ) → ∃ 𝑘 𝑥𝐴 𝐵 ( 𝑓𝑘 ) = 𝑧 )
71 67 68 70 syl2anc ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ∃ 𝑘 𝑥𝐴 𝐵 ( 𝑓𝑘 ) = 𝑧 )
72 65 71 r19.29a ( ( ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ( 𝑓𝑧 ) = ( 2nd𝑧 ) )
73 26 sselda ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) → 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) )
74 eliun ( 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ↔ ∃ 𝑥𝐴 𝑧 ∈ ( { 𝑥 } × 𝐵 ) )
75 73 74 sylib ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) → ∃ 𝑥𝐴 𝑧 ∈ ( { 𝑥 } × 𝐵 ) )
76 46 72 75 r19.29af ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 ∈ ran 𝑓 ) → ( 𝑓𝑧 ) = ( 2nd𝑧 ) )
77 nfv 𝑘 ( 𝜑𝑦 𝑥𝐴 𝐵 )
78 nfcv 𝑘
79 16 78 nfel 𝑘 𝑦 / 𝑘 𝐶 ∈ ℂ
80 77 79 nfim 𝑘 ( ( 𝜑𝑦 𝑥𝐴 𝐵 ) → 𝑦 / 𝑘 𝐶 ∈ ℂ )
81 eleq1w ( 𝑘 = 𝑦 → ( 𝑘 𝑥𝐴 𝐵𝑦 𝑥𝐴 𝐵 ) )
82 81 anbi2d ( 𝑘 = 𝑦 → ( ( 𝜑𝑘 𝑥𝐴 𝐵 ) ↔ ( 𝜑𝑦 𝑥𝐴 𝐵 ) ) )
83 14 eleq1d ( 𝑘 = 𝑦 → ( 𝐶 ∈ ℂ ↔ 𝑦 / 𝑘 𝐶 ∈ ℂ ) )
84 82 83 imbi12d ( 𝑘 = 𝑦 → ( ( ( 𝜑𝑘 𝑥𝐴 𝐵 ) → 𝐶 ∈ ℂ ) ↔ ( ( 𝜑𝑦 𝑥𝐴 𝐵 ) → 𝑦 / 𝑘 𝐶 ∈ ℂ ) ) )
85 nfcv 𝑥 𝑘
86 85 34 nfel 𝑥 𝑘 𝑥𝐴 𝐵
87 32 86 nfan 𝑥 ( 𝜑𝑘 𝑥𝐴 𝐵 )
88 3 adantllr ( ( ( ( 𝜑𝑘 𝑥𝐴 𝐵 ) ∧ 𝑥𝐴 ) ∧ 𝑘𝐵 ) → 𝐶 ∈ ℝ )
89 88 recnd ( ( ( ( 𝜑𝑘 𝑥𝐴 𝐵 ) ∧ 𝑥𝐴 ) ∧ 𝑘𝐵 ) → 𝐶 ∈ ℂ )
90 eliun ( 𝑘 𝑥𝐴 𝐵 ↔ ∃ 𝑥𝐴 𝑘𝐵 )
91 90 biimpi ( 𝑘 𝑥𝐴 𝐵 → ∃ 𝑥𝐴 𝑘𝐵 )
92 91 adantl ( ( 𝜑𝑘 𝑥𝐴 𝐵 ) → ∃ 𝑥𝐴 𝑘𝐵 )
93 87 89 92 r19.29af ( ( 𝜑𝑘 𝑥𝐴 𝐵 ) → 𝐶 ∈ ℂ )
94 80 84 93 chvarfv ( ( 𝜑𝑦 𝑥𝐴 𝐵 ) → 𝑦 / 𝑘 𝐶 ∈ ℂ )
95 94 adantlr ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑦 𝑥𝐴 𝐵 ) → 𝑦 / 𝑘 𝐶 ∈ ℂ )
96 18 27 31 76 95 fsumf1o ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → Σ 𝑦 𝑥𝐴 𝐵 𝑦 / 𝑘 𝐶 = Σ 𝑧 ∈ ran 𝑓 ( 2nd𝑧 ) / 𝑘 𝐶 )
97 17 96 eqtrid ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → Σ 𝑘 𝑥𝐴 𝐵 𝐶 = Σ 𝑧 ∈ ran 𝑓 ( 2nd𝑧 ) / 𝑘 𝐶 )
98 97 eqcomd ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → Σ 𝑧 ∈ ran 𝑓 ( 2nd𝑧 ) / 𝑘 𝐶 = Σ 𝑘 𝑥𝐴 𝐵 𝐶 )
99 nfcv 𝑥 𝑧
100 99 41 nfel 𝑥 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 )
101 32 100 nfan 𝑥 ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) )
102 xp2nd ( 𝑧 ∈ ( { 𝑥 } × 𝐵 ) → ( 2nd𝑧 ) ∈ 𝐵 )
103 102 adantl ( ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ( 2nd𝑧 ) ∈ 𝐵 )
104 3 ralrimiva ( ( 𝜑𝑥𝐴 ) → ∀ 𝑘𝐵 𝐶 ∈ ℝ )
105 104 adantlr ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) → ∀ 𝑘𝐵 𝐶 ∈ ℝ )
106 105 adantr ( ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ∀ 𝑘𝐵 𝐶 ∈ ℝ )
107 nfcsb1v 𝑘 ( 2nd𝑧 ) / 𝑘 𝐶
108 107 nfel1 𝑘 ( 2nd𝑧 ) / 𝑘 𝐶 ∈ ℝ
109 csbeq1a ( 𝑘 = ( 2nd𝑧 ) → 𝐶 = ( 2nd𝑧 ) / 𝑘 𝐶 )
110 109 eleq1d ( 𝑘 = ( 2nd𝑧 ) → ( 𝐶 ∈ ℝ ↔ ( 2nd𝑧 ) / 𝑘 𝐶 ∈ ℝ ) )
111 108 110 rspc ( ( 2nd𝑧 ) ∈ 𝐵 → ( ∀ 𝑘𝐵 𝐶 ∈ ℝ → ( 2nd𝑧 ) / 𝑘 𝐶 ∈ ℝ ) )
112 111 imp ( ( ( 2nd𝑧 ) ∈ 𝐵 ∧ ∀ 𝑘𝐵 𝐶 ∈ ℝ ) → ( 2nd𝑧 ) / 𝑘 𝐶 ∈ ℝ )
113 103 106 112 syl2anc ( ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ( 2nd𝑧 ) / 𝑘 𝐶 ∈ ℝ )
114 74 biimpi ( 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) → ∃ 𝑥𝐴 𝑧 ∈ ( { 𝑥 } × 𝐵 ) )
115 114 adantl ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) → ∃ 𝑥𝐴 𝑧 ∈ ( { 𝑥 } × 𝐵 ) )
116 101 113 115 r19.29af ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) → ( 2nd𝑧 ) / 𝑘 𝐶 ∈ ℝ )
117 116 adantlr ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) → ( 2nd𝑧 ) / 𝑘 𝐶 ∈ ℝ )
118 xp1st ( 𝑧 ∈ ( { 𝑥 } × 𝐵 ) → ( 1st𝑧 ) ∈ { 𝑥 } )
119 elsni ( ( 1st𝑧 ) ∈ { 𝑥 } → ( 1st𝑧 ) = 𝑥 )
120 118 119 syl ( 𝑧 ∈ ( { 𝑥 } × 𝐵 ) → ( 1st𝑧 ) = 𝑥 )
121 120 102 jca ( 𝑧 ∈ ( { 𝑥 } × 𝐵 ) → ( ( 1st𝑧 ) = 𝑥 ∧ ( 2nd𝑧 ) ∈ 𝐵 ) )
122 simplll ( ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) ∧ ( ( 1st𝑧 ) = 𝑥 ∧ ( 2nd𝑧 ) ∈ 𝐵 ) ) → 𝜑 )
123 simplr ( ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) ∧ ( ( 1st𝑧 ) = 𝑥 ∧ ( 2nd𝑧 ) ∈ 𝐵 ) ) → 𝑥𝐴 )
124 4 ralrimiva ( ( 𝜑𝑥𝐴 ) → ∀ 𝑘𝐵 0 ≤ 𝐶 )
125 122 123 124 syl2anc ( ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) ∧ ( ( 1st𝑧 ) = 𝑥 ∧ ( 2nd𝑧 ) ∈ 𝐵 ) ) → ∀ 𝑘𝐵 0 ≤ 𝐶 )
126 121 125 sylan2 ( ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → ∀ 𝑘𝐵 0 ≤ 𝐶 )
127 nfcv 𝑘 0
128 nfcv 𝑘
129 127 128 107 nfbr 𝑘 0 ≤ ( 2nd𝑧 ) / 𝑘 𝐶
130 109 breq2d ( 𝑘 = ( 2nd𝑧 ) → ( 0 ≤ 𝐶 ↔ 0 ≤ ( 2nd𝑧 ) / 𝑘 𝐶 ) )
131 129 130 rspc ( ( 2nd𝑧 ) ∈ 𝐵 → ( ∀ 𝑘𝐵 0 ≤ 𝐶 → 0 ≤ ( 2nd𝑧 ) / 𝑘 𝐶 ) )
132 131 imp ( ( ( 2nd𝑧 ) ∈ 𝐵 ∧ ∀ 𝑘𝐵 0 ≤ 𝐶 ) → 0 ≤ ( 2nd𝑧 ) / 𝑘 𝐶 )
133 103 126 132 syl2anc ( ( ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ∧ 𝑥𝐴 ) ∧ 𝑧 ∈ ( { 𝑥 } × 𝐵 ) ) → 0 ≤ ( 2nd𝑧 ) / 𝑘 𝐶 )
134 101 133 115 r19.29af ( ( 𝜑𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) → 0 ≤ ( 2nd𝑧 ) / 𝑘 𝐶 )
135 134 adantlr ( ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) ∧ 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) → 0 ≤ ( 2nd𝑧 ) / 𝑘 𝐶 )
136 25 117 135 26 fsumless ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → Σ 𝑧 ∈ ran 𝑓 ( 2nd𝑧 ) / 𝑘 𝐶 ≤ Σ 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ( 2nd𝑧 ) / 𝑘 𝐶 )
137 98 136 eqbrtrrd ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → Σ 𝑘 𝑥𝐴 𝐵 𝐶 ≤ Σ 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ( 2nd𝑧 ) / 𝑘 𝐶 )
138 14 15 16 cbvsum Σ 𝑘𝐵 𝐶 = Σ 𝑦𝐵 𝑦 / 𝑘 𝐶
139 138 a1i ( 𝜑 → Σ 𝑘𝐵 𝐶 = Σ 𝑦𝐵 𝑦 / 𝑘 𝐶 )
140 139 sumeq2sdv ( 𝜑 → Σ 𝑥𝐴 Σ 𝑘𝐵 𝐶 = Σ 𝑥𝐴 Σ 𝑦𝐵 𝑦 / 𝑘 𝐶 )
141 vex 𝑥 ∈ V
142 vex 𝑦 ∈ V
143 141 142 op2ndd ( 𝑧 = ⟨ 𝑥 , 𝑦 ⟩ → ( 2nd𝑧 ) = 𝑦 )
144 143 eqcomd ( 𝑧 = ⟨ 𝑥 , 𝑦 ⟩ → 𝑦 = ( 2nd𝑧 ) )
145 144 csbeq1d ( 𝑧 = ⟨ 𝑥 , 𝑦 ⟩ → 𝑦 / 𝑘 𝐶 = ( 2nd𝑧 ) / 𝑘 𝐶 )
146 145 eqcomd ( 𝑧 = ⟨ 𝑥 , 𝑦 ⟩ → ( 2nd𝑧 ) / 𝑘 𝐶 = 𝑦 / 𝑘 𝐶 )
147 nfv 𝑘 ( ( 𝜑𝑥𝐴 ) ∧ 𝑦𝐵 )
148 16 nfel1 𝑘 𝑦 / 𝑘 𝐶 ∈ ℂ
149 147 148 nfim 𝑘 ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑦𝐵 ) → 𝑦 / 𝑘 𝐶 ∈ ℂ )
150 eleq1w ( 𝑘 = 𝑦 → ( 𝑘𝐵𝑦𝐵 ) )
151 150 anbi2d ( 𝑘 = 𝑦 → ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑘𝐵 ) ↔ ( ( 𝜑𝑥𝐴 ) ∧ 𝑦𝐵 ) ) )
152 151 83 imbi12d ( 𝑘 = 𝑦 → ( ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑘𝐵 ) → 𝐶 ∈ ℂ ) ↔ ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑦𝐵 ) → 𝑦 / 𝑘 𝐶 ∈ ℂ ) ) )
153 3 recnd ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑘𝐵 ) → 𝐶 ∈ ℂ )
154 149 152 153 chvarfv ( ( ( 𝜑𝑥𝐴 ) ∧ 𝑦𝐵 ) → 𝑦 / 𝑘 𝐶 ∈ ℂ )
155 154 anasss ( ( 𝜑 ∧ ( 𝑥𝐴𝑦𝐵 ) ) → 𝑦 / 𝑘 𝐶 ∈ ℂ )
156 146 1 2 155 fsum2d ( 𝜑 → Σ 𝑥𝐴 Σ 𝑦𝐵 𝑦 / 𝑘 𝐶 = Σ 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ( 2nd𝑧 ) / 𝑘 𝐶 )
157 140 156 eqtrd ( 𝜑 → Σ 𝑥𝐴 Σ 𝑘𝐵 𝐶 = Σ 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ( 2nd𝑧 ) / 𝑘 𝐶 )
158 157 adantr ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → Σ 𝑥𝐴 Σ 𝑘𝐵 𝐶 = Σ 𝑧 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ( 2nd𝑧 ) / 𝑘 𝐶 )
159 137 158 breqtrrd ( ( 𝜑 ∧ ( ( 𝑓 : 𝑥𝐴 𝐵1-1-onto→ ran 𝑓 ∧ ∀ 𝑙 𝑥𝐴 𝐵 ( 2nd ‘ ( 𝑓𝑙 ) ) = 𝑙 ) ∧ ran 𝑓 𝑥𝐴 ( { 𝑥 } × 𝐵 ) ) ) → Σ 𝑘 𝑥𝐴 𝐵 𝐶 ≤ Σ 𝑥𝐴 Σ 𝑘𝐵 𝐶 )
160 13 159 exlimddv ( 𝜑 → Σ 𝑘 𝑥𝐴 𝐵 𝐶 ≤ Σ 𝑥𝐴 Σ 𝑘𝐵 𝐶 )